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address erosion, scour, depos~ion, impact and hydrostatic forces; provide that the design and maintenance of project elements be coordinated with the local jurisdiction and/or agency responsible for flood control within the commun~y. How Does the NFJP Address Development On Alluviat Fans? The NFIP identifies alluvial fan hazards on FIRMs as Zone AD and provides information on flood depths and velocities. AD zones are Special Flood Hazards Areas (SFHA) subject to inundation by 1 DO-year sheet-type flow, which are sometimes associated w~h high velocities. n the community's FIRM identifies AD zones with depths and vel""ities, construction within those alluvial fan areas are subject to certain regulations (in addition to those which apply to ali SFHA's) found in Chapter 44 of the Code of Federal Regulations, Part 60.3: Elevate lowest floor (including basement) above the highest adjacent grade to atleasl as high as the depth number specffied on the FIRM. (It is recommended, however, thallhe depth of flow assumed for a particular site should take into consideration local topographic anomalies when determining the elevation of any flood protection measure.) Mechanical and util~y equipment must also be placed above the depth of flooding. Provide adequate drainage paths around structures on slopes, to guide fioodwater around and away from proposed structures. Do not deflect floodflow onto adjacent properties. As part of the FIRM revision process, FEMA will review the development plans submitted by owners of projects who request the removal of their property from the SFHA. To ensure that these projects are in fact protected from alluvial fan flood hazards, FEMA's review criteria require that the con- struction include elements which: do not cause the distur- bance of natural flood processes on the fan; allow for the safe collection, passage, and disposal of flood-related water, sedi- ment and debris without negative impact to adjacent property; 12 With knowledge of local cond~ions and in the interest of safety, state and community officials may set higher standards for construction in floodplain areas. As with all flooding s~uations, FEMA encourages local jurisdictions to adopt fioodplain management measures which are more tailored to the community's particular flood problems. This is especially Important for communities prone to alluvial fan flood hazards, where each fan presents a unique set of flood conditions. It should be noted that the provisions of Section 60.3 are minimum requirements; buildings constructed according to these rules alone will not provide adequate protection against high velocities or debris loads unless add~ional measures are undertaken. The unique qualities of each fan formation and its attendant hazards requires individual study and strategic planning using the guidance of government officials, engineers, hydrologists, and geologists. It is hoped that this publication has offered sufficient information regarding the importance of guiding development on alluvial fans to provide the impetus fo, local knowledge and expertise. Intensified commitment to offset CUffent and future lIoad losses on fans wili g,eatly complement the work of professional groups and public agencies as they begin to develop management and construction standards for these special arid west flood hazards.